Anime episode progress can still show 0% for older sessions that have watch-time and subtitle timing but no persisted ended_media_ms checkpoint. Recover progress from the latest retained subtitle/event segment end so already-recorded sessions render a useful progress percentage.
Acceptance Criteria
getAnimeEpisodes returns the latest known session position even when ended_media_ms is null but subtitle/event timing exists.
Existing ended-session metrics and aggregation totals do not regress.
Regression coverage locks the fallback behavior.
Implementation Notes
Added a query-side fallback for anime episode progress: when the newest session for a video has no persisted ended_media_ms, getAnimeEpisodes now uses the latest retained subtitle-line or session-event segment_end_ms from that same session. This recovers useful progress for already-recorded sessions that have timing data but predate or missed checkpoint persistence.
Verification: bun test src/core/services/immersion-tracker/__tests__/query.test.ts passed. bun run typecheck passed.
